1. Field of the Invention
This invention relates to an air gun for shooting a bullet by a supplied compressed gas and performing blow-back for shooting the next bullet by moving a sliding portion backward in the air gun.
2. Description of the Background Art
A conventional air gun performing blow-back for the next bullet shoot has a compressed gas air chamber, an opening-closing valve and a switching valve. The compressed gas air chamber stores the supplied compressed gas in the air gun for shooting the bullet by the compressed gas. The opening-closing valve releases the compressed gas for shooting the bullet. The switching valve switches flow-out portions of the sent compressed gas by setting the opening-closing valve to an opening state. The opening-closing valve is arranged within a grip portion and is set to the opening state by striking a valve rod with a hammer, and supplies the compressed gas within the compressed gas air chamber. The switching valve is arranged within a slide or the grip portion and switches the flow-out portions of the supplied compressed gas by setting the opening-closing valve to be opened.
Namely, for example, an air gun shown in FIG. 19 is known as a conventional automatic type air gun using a compressed carbonic acid gas, or the air, etc.
A conventional example 1 of the conventional air gun will next be explained. Reference numeral 401 designates an air gun. In the following description, an operation of the air gun 401 will be explained from a state in which a bullet W is supported within a rubber chamber 408 and a switching valve 409 is moved backward in the air gun 401 at any time against the biasing force of a valve spring 412 until the bullet W itself is shot. First, a trigger 402 is pulled to shoot the bullet W. A hammer 403 is thus rotated in an arrow direction and presses against a valve pin 404. Since the valve pin 404 is pressed, a valve 406 is set to an opening state so that a compressed gas stored in an accumulating pressure chamber 405 is flowed into the side of a slide 407 through the valve 406. At this time, the switching valve 409 closes the side of a cylinder 413 so as not to flow-out the compressed gas to the side of the cylinder 413. The compressed gas flowed into the side of the slide 407 is flowed into a side of the bullet W within the rubber chamber 408 and pushes-out the bullet W and forcibly shoots the bullet W from a muzzle through the interior of an outer barrel 410.
After the bullet W is shot, there is no bullet W in the rubber chamber 408 so that the switching valve 409 is pushed back to an unillustrated muzzle side by the biasing force of the valve spring 412 and the flow-out of the compressed gas onto the unillustrated muzzle side is stopped and the cylinder side is set to an opening state. Accordingly, the compressed gas prevented from being flowed-out onto the muzzle side is flowed into the cylinder 413 and moves the cylinder 413 and the slide 407 backward in the air gun 401 against the biasing force of a slide spring 414 so that the hammer 403 is inclined backward. Further, when the compressed gas is returned to the muzzle side, an end tip of the slide 407 on its muzzle side pushes the next bullet supplied from a bullet storage 411 so that the rubber chamber 408 is charged with this bullet and the next bullet shoot is prepared.
In contrast to this, there is a second conventional example of the conventional air gun as explained in the following description based on FIG. 20.
Reference numeral 501 designates an air gun. An operation of the air gun 501 will next be explained from a state in which a bullet W is supported within a charging packing 508. A switching valve 509 in this second conventional example differs from that in the first conventional example as follows. Namely, in a state in which the charging packing 508 is charged with the bullet W, a compressed gas unpressed by the bullet and accumulated in an accumulating pressure chamber 505 in a normal state can be flowed out to a side of the bullet W charged in the charging packing 509 and is not flowed out to the side of a cylinder 513. When the compressed gas is rapidly flowed out to an unillustrated muzzle side after the bullet W is shot, the switching valve 509 is moved in a muzzle direction by a negative pressure of the compressed gas and closes the side of a piston block 507 and opens the side of the cylinder 513 such that the compressed gas is flowed out to the side of the cylinder 513.
First, a trigger 502 is pulled to shoot the bullet W. Thus, a hammer 503 is rotated in an arrow direction and presses against a valve rod 504. Since the valve rod 504 is pressed, a valve 506 is set to an opening state and the compressed gas stored in the accumulating pressure chamber 505 is flowed into the side of the piston block 507 through the valve 506. In the piston block 507, the switching valve 509 sets a side of the charging packing 508 to an opening state by the biasing force of a spring 512, and a rear side end portion of the switching valve 509 in the air gun 501 closes the side of the cylinder 513. Accordingly, the compressed gas flowed into the side of the piston block 507 is flowed into a side of the bullet W within the charging packing 508 and pushes out the bullet W so that this bullet is forcibly shot from the muzzle through the interior of an outer barrel 510.
After the bullet W is shot, there is no bullet W in the charging packing 508 so that the compressed gas is rapidly flowed to the side of the charging packing 508 and the switching valve 509 is pushed back to the unillustrated muzzle side against the biasing force of the valve spring 512 by a negative pressure caused by the flow of the compressed gas. Thus, flow-out of the compressed gas to the unillustrated muzzle side is stopped. Accordingly, the compressed gas prevented from being flowed-out to the muzzle side is flowed into the piston block 507 and moves the piston block 507 backward in the air gun 501 so that the hammer 503 is inclined backward. Further, when the compressed gas is returned to the muzzle side, an end tip of the piston block 507 on its muzzle side pushes the next bullet supplied from a bullet storage 511 so that the charging packing 508 is charged with this bullet and shooting of the next bullet is prepared.
As mentioned above, in the conventional air gun, the next gun is automatically supplied by switching a state in which the compressed gas is flowed-out to the muzzle side within a slide slidably arranged from the muzzle side to a gun rear end in an upper portion of the air gun, or is flowed-out to the gun rear end. However, the switching valve for switching flow paths of the compressed gas is arranged within the slide slidable in the upper portion of the air gun.
Further, other conventional air guns using the compressed gas are shown in U.S. Pat. Nos. 2,817,328 and 5,476,087. Each of these air guns separately has a valve for discharging the compressed gas for shooting a bullet and a mechanism for charging the gun with the bullet and preparing shooting of the next bullet.
As mentioned above, the opening-closing valve for supplying the compressed gas and the switching valve or mechanism are separately arranged in the conventional method. This switching valve or mechanism supplies the supplied compressed gas to the charged bullet and then stops the supply of the compressed gas to a bullet side, and performs a switching operation such that the compressed gas is supplied to move the cylinder, etc. backward in the gun so as to prepare for shooting of the next bullet.
However, in accordance with the conventional method, since the opening-closing valve and the switching valve are separately arranged, the number of constructional members is increased and it is difficult to make the entire structure compact. A problem also exists in that the compressed gas is uselessly used by each valve and passage volumes of the compressed gas between the valves. Further, it is difficult to make the gun compact.